In Italy, the 2016 campaign of Seveso inspections has been the first after the Seveso III (European Directive 2012/18/UE) implementation. That inspection plan involved the audit of about 150 of the over 450 upper tier establishments. During the 2016-2017 campaigns, about a thousand documents of operating experience OE reports have been gathered. The aim of the paper is to describe the methods adopted for exploiting in a more formal way this valuable information treasure. The study adopts cognitive methods, based on different taxonomies and classifications, to extract knowledge useful for different aims. The paper shows some examples to exploit alerts for stakeholders. Results of extracted knowledge are valuable for inspectors to address future inspections, and for regulators to issue new guidelines.